Technological Field
This disclosure relates to radio frequency (RF) circuits and circuit design. More particularly, this disclosure relates to a low noise amplifier (LNA) within RF transceiver.
Related Art
A wireless device (e.g., a cellular phone or a smartphone) in a wireless communication system can transmit and receive data for two-way communication. The wireless device can include a transmitter for data transmission and a receiver for data reception. For data transmission, the transmitter may modulate a radio frequency (RF) carrier signal with data to obtain a modulated signal, amplify the modulated signal to obtain an output RF signal having the proper transmit power level, and transmit the output RF signal via an antenna to a base station. For data reception, the receiver can obtain a received RF signal via the antenna and may amplify and process the received RF signal to recover data sent by the base station.
A wireless device can have amplifiers of different types for different purposes. For example, a wireless device may include a low noise amplifier (LNA) in a receiver, a driver amplifier (DA) and a power amplifier (PA) in a transmitter, and a variable gain amplifier (VGA) in the receiver and/or transmitter. The wireless device can have multiple amplifiers having outputs coupled together, with each amplifier being either enabled to provide an output signal or disabled to provide no output signal.